In general, boats (ships) can be classified into a mono hull and a multi hull (typically, catamaran), depending on the number of hulls providing buoyancy.
Monohulls, ships with one hull providing buoyancy, has excellent traveling ability or running ability, but the center buoyancy is stable less than multi hulls, so they have a defect of too much roll that is an up-down swing of the sides by waves or wind and pitch that is an up-down swing of the bow and the stern. On the contrary, in multihulls, ships with two or more hulls providing buoyancy, particularly, as for catamarans that are typical ones, the center of buoyancy is divided to both sides, so the balance can be kept stable, but the running ability is poor in comparison to monohulls.